So, by implication, you're suggesting the US exercised atomic power over peace talks? Doesn't that seem...well, improbably monstrous? Having the capacity to accept peaceful surrender, but instead opting to drop back-to-back ultra weapons, installing kill tens of thousands while irradiating everything for decades to come...

That is exactly what I am suggesting. Given the tenor of the war, it does not seem improbable, monstrous as it was.

What would be their motivation? I don't believe their purpose was to solidify technological showmanship over Russia. Why, then?

Among the many motivations -

1. A desire for an unconditional surrender, operating off the belief that it was the conditional nature of the armistice that ended WWI that led to the second war. This perspective, of course, ignores the Allies' previous mistakes in drafting the Treaty of Versailles, along with British and French mismanagement of their Asian colonies, that played major contributing roles in the outbreak of the Pacific War. This trickled down into rhetoric about "staying the course" and "seeing the job through."
2. The conquest of Japan as a geostrategic asset in the anticipated rivalry with the Soviet Union. The Cold War was coming, simply based on the US and USSR having the greatest resource bases and industrial capacity, along with opposed economic and ideological systems. A negotiated peace, particularly if mediated by the Soviets, would have likely left Japan as a more neutral actor in the region, as opposed to the staunch US ally that it became.
3. Unfathomable racism by modern standards. A negotiated peace would be treating the Japanese like equals, at a time when most Americans thought of the Japanese as sub-human vermin, and many Europeans as uppity players at empire. Much of the higher Allied leadership would have found negotiation with Japan to be personally insulting, akin to arguing with a dog over who gets the steak and who gets the scraps. In their eyes, the Japanese didn't deserve to be negotiated with like white men.
4. Desire to reinforce American and European imperial hegemony over the Western Pacific. Japan's ascendancy, combined with its previous defeat of Russia in 1905, had great symbolic value to East Asians, even those who fought against Japan. It stood as proof that they could stand against the Western imperialist powers and potentially prevail, establishing self-determination. This is in part why there was massive, broad-based support for Japan in India throughout the war. For the Western powers, this suggested that Karthago delenda est.
5. Political expediency. American propaganda had spend the previous four years reinforcing how Pearl Harbor was an act of unparalleled cravenness, how the Japs were savage, bloodthirsty creatures who raped babies for pleasure, and that the war represented the consummate, orgasmic expression of American greatness and patriotism. Negotiating with such caricatures would have been extremely politically risky. Furthermore, Roosevelt only received 53% of the popular vote in 1944, less than he did in the peacetime 1940 election, leaving him in a surprisingly vulnerable position.
6. Desire to make use of the capacity that the US had. The Bomb was there, the European war had ended too early to use it, and military analysts love data on new and experimental devices, especially when used on live targets. Before Hiroshima, no one knew what the various effects would be on living things and structures at particular radii; they had educated guesses at most. It was only after the attack that people became aware of fallout and radiation sickness.

I mean, I'm open to possibility here, but you're offering a position wherein US senior leadership consciously choose unfathomable devastation over...well, over peace -- and in doing so, effectively committed one of the most barbaric choices in human history (if in fact it was within their capacity to avoid).

Arendt called it "the banality of evil." The United States, and especially its leadership, had experienced essentially none of the particular horrors that WWII unleashed upon the world. At a certain level, the war became less about soldiers and civilians being slaughtered, and more about numbers on a piece of paper, and performance benchmarks to be reached. The Japanese were thought of less and less as people, and more as the inhuman enemy. Firebombing civilian areas with relatively little military value and killing tens of thousands of civilians could be waved off, as it "damaged their war effort" and potentially "saved lives" (imagine that, saving lives by ending ten times as many). Using a city as a testing ground for your new superweapon, precisely because it had not previously been damaged, is justified because "they started it."

"However, the senior leadership of the Japanese Army took the news [about Nagasaki] in stride, grossly underestimating the scale of the attack. With the support of Minister of War Anami, they started preparing to impose martial law on the nation, to stop anyone attempting to make peace."

There are always countervailing factions within governments, especially panicky ones who are convinced of defeat and existential annihilation.

That is exactly what I am suggesting. Given the tenor of the war, it does not seem improbable, monstrous as it was.

Among the many motivations -

1. A desire for an unconditional surrender, operating off the belief that it was the conditional nature of the armistice that ended WWI that led to the second war. This perspective, of course, ignores the Allies' previous mistakes in drafting the Treaty of Versailles, along with British and French mismanagement of their Asian colonies, that played major contributing roles in the outbreak of the Pacific War. This trickled down into rhetoric about "staying the course" and "seeing the job through."
2. The conquest of Japan as a geostrategic asset in the anticipated rivalry with the Soviet Union. The Cold War was coming, simply based on the US and USSR having the greatest resource bases and industrial capacity, along with opposed economic and ideological systems. A negotiated peace, particularly if mediated by the Soviets, would have likely left Japan as a more neutral actor in the region, as opposed to the staunch US ally that it became.
3. Unfathomable racism by modern standards. A negotiated peace would be treating the Japanese like equals, at a time when most Americans thought of the Japanese as sub-human vermin, and many Europeans as uppity players at empire. Much of the higher Allied leadership would have found negotiation with Japan to be personally insulting, akin to arguing with a dog over who gets the steak and who gets the scraps. In their eyes, the Japanese didn't deserve to be negotiated with like white men.
4. Desire to reinforce American and European imperial hegemony over the Western Pacific. Japan's ascendancy, combined with its previous defeat of Russia in 1905, had great symbolic value to East Asians, even those who fought against Japan. It stood as proof that they could stand against the Western imperialist powers and potentially prevail, establishing self-determination. This is in part why there was massive, broad-based support for Japan in India throughout the war. For the Western powers, this suggested that Karthago delenda est.
5. Political expediency. American propaganda had spend the previous four years reinforcing how Pearl Harbor was an act of unparalleled cravenness, how the Japs were savage, bloodthirsty creatures who raped babies for pleasure, and that the war represented the consummate, orgasmic expression of American greatness and patriotism. Negotiating with such caricatures would have been extremely politically risky. Furthermore, Roosevelt only received 53% of the popular vote in 1944, less than he did in the peacetime 1940 election, leaving him in a surprisingly vulnerable position.
6. Desire to make use of the capacity that the US had. The Bomb was there, the European war had ended too early to use it, and military analysts love data on new and experimental devices, especially when used on live targets. Before Hiroshima, no one knew what the various effects would be on living things and structures at particular radii; they had educated guesses at most. It was only after the attack that people became aware of fallout and radiation sickness.

Arendt called it "the banality of evil." The United States, and especially its leadership, had experienced essentially none of the particular horrors that WWII unleashed upon the world. At a certain level, the war became less about soldiers and civilians being slaughtered, and more about numbers on a piece of paper, and performance benchmarks to be reached. The Japanese were thought of less and less as people, and more as the inhuman enemy. Firebombing civilian areas with relatively little military value and killing tens of thousands of civilians could be waved off, as it "damaged their war effort" and potentially "saved lives" (imagine that, saving lives by ending ten times as many). Using a city as a testing ground for your new superweapon, precisely because it had not previously been damaged, is justified because "they started it."

There are always countervailing factions within governments, especially panicky ones who are convinced of defeat and existential annihilation.

Just face it guy, no one - including you - wants to crawl through ten miles of jungle swarming with forces aching to place your genitals into your mouth

Just face it guy, no one - including you - wants to crawl through ten miles of jungle swarming with forces aching to place your genitals into your mouth

unless you're one fucked up psychopath.

That sort of thing is called "historical revisionism." But whatever, it's just the internet. Anyway, he acts like demonizing the enemy is an act known only to western civilization. Of course that's the true enemy - western civilization, especially because it was built by eeeeeeeevilll white males. But I didn't see anybody else making much of an effort to crawl out of their mud huts and build skyscrapers.

"Everyone has a plan till they get punched in the mouth." Mike Tyson
“Culture?” says Paul McCartney. “This isn't culture. It's just a good laugh.”

No, because the United States mainland lay 5,000 miles across the ocean, and Japan had no capability of sending an attacking force that distance, or any distance for that matter. Which means that, if American soldiers ended up having to do such a thing, it was because American war command had decided unilaterally to send its soldiers into this mess. In July of 1945, Japan did not constitute an aggressive threat to anyone, as even its forces in China were running out of materiel and support capabilities.

Japan did not want to surrender, and there was no need for it to surrender. There could have easily been an armistice drawn that did not declare a winner or loser, and a treaty created that granted favorable terms to the Allies, securely ending the war. This did not happen because the US, in particular, wanted to force Japan into an unconditional surrender, maximizing its gains in the war at the further expense of Japan. It was purely out of aggression on the part of the US.

That sort of thing is called "historical revisionism." But whatever, it's just the internet. Anyway, he acts like demonizing the enemy is an act known only to western civilization. Of course that's the true enemy - western civilization, especially because it was built by eeeeeeeevilll white males. But I didn't see anybody else making much of an effort to crawl out of their mud huts and build skyscrapers.

The problem I have with Western civilization is in its essentially predatory character, and the lack of effective checks placed upon it. If a society outside of Western civilization has something that the power elite of the West want, and is unwilling to sell it to them, they will do whatever it takes, up to and including the destruction of that society, in order to obtain it. Practically nothing short of a nuclear arsenal will stop them, and as we see in the case of Pakistan, sometimes that doesn't even work.

And as much as I like skyscrapers, what if those people are perfectly happy with their mud huts?

No, because the United States mainland lay 5,000 miles across the ocean, and Japan had no capability of sending an attacking force that distance, or any distance for that matter. Which means that, if American soldiers ended up having to do such a thing, it was because American war command had decided unilaterally to send its soldiers into this mess. In July of 1945, Japan did not constitute an aggressive threat to anyone, as even its forces in China were running out of materiel and support capabilities.

Japan did not want to surrender, and there was no need for it to surrender. There could have easily been an armistice drawn that did not declare a winner or loser, and a treaty created that granted favorable terms to the Allies, securely ending the war. This did not happen because the US, in particular, wanted to force Japan into an unconditional surrender, maximizing its gains in the war at the further expense of Japan. It was purely out of aggression on the part of the US.

I guess I'd liken it to starcraft. People would ask for quarter, to which i gave them none.

So, by implication, you're suggesting the US exercised atomic power over peace talks? Doesn't that seem...well, improbably monstrous? Having the capacity to accept peaceful surrender, but instead opting to drop back-to-back ultra weapons, instantly kill tens of thousands while irradiating everything for decades to come...

What would be their motivation? I don't believe their purpose was to solidify technological showmanship over Russia. Why, then?

This was a significant part of the motivation. There was already tension with the USSR when the war in Europe was concluding, and some Allied commanders talked about marching right through Germany to take on the Soviets, while they were still weakened by their heavy losses in the war. The USSR had taken control of eastern Europe by the summer of 1945, and actual demonstration of an atomic bomb was a good way to for the U.S. to flex its muscles. Stalin already knew of the existence of the bomb thanks to Soviet spies, but no one had seen its effect on a real target.

I've been called a criminal, a terrorist, and a threat to the known universe. But everything you were told is a lie. The truth is, they've taken our freedom, our home, and our future. The time has come for all humanity to take a stand...